1. Field of the Invention
The invention relates to a device and a method for the covering of, for example, a tracer or the like, which in general is located in the base part of a projectile body, and relates to the concept that the tracer or similar contents must be sealed in an airtight manner because the moisture, etc., that would otherwise enter can have the result that, for example, the tracer pyrotechnic material no longer burns or burns inadequately. To this end, a method is proposed in which a cover, preferably a cover ring, is pressed radially into a groove contour of the projectile body, which preferably extends continuously around the circumference, during the forming process by an axial advance motion of a (rigid) die, preferably made of metal. The die has an outer diameter that depends on the axial position of the die relative to that of the cover.
2. Description of the Background Art
In practice, provision is made for an airtight seal to be implemented by means of a cover disk, etc., generally made of brass. This is secured in place by additional parts, such as, e.g., a cover ring. In this design, the cover ring is retained by forming of the material of the projectile body, for example. Other solutions are known along the lines of an additional screw or nut being screwed into the base part of the projectile body.
The disadvantage of forming resides in that, among other factors, contradictory demands are often placed on the projectile body material. Material properties that are hard or exhibit little or no deformability are a precondition for final ballistic effectiveness, while soft or ductile material properties are the precondition for the forming process such as crimping, peening, etc. Therefore, the region of the projectile body material that is to be formed is converted into a soft or ductile state by the application of heat treatment methods; however, this is very complicated and is both cost-intensive and time-intensive. Moreover, process stability must be maintained at great effort. The formation of cracks in the material, which can arise during hardening or forming, cannot be prevented even by the heat treatment method that follows or that has preceded the forming process, and can, as potential failure sources, result in the failure of the cover. In contrast, screws and nuts need only be subjected to a surface treatment, for example hard anodizing, but the effort at assembly is greater, as measures for securing the screws are necessary. Guide surfaces for improved assembly require a commensurate installation space. Moreover, the weight of a screwed connection for covering the tracer is greater than that of a cover ring.